---
id: zipfile-deflate64
version: "0.2.0"
license: Apache 2.0
license_treatment: permissive
maintenance: dormant
---

# zipfile-deflate64 — Extract Deflate64 ZIP archives with Python's zipfile API.

License: permissive · Maintenance: dormant · Downloads: 1.1M/mo

## What it is and what it does

zipfile-deflate64 solves a specific compatibility problem: recent versions of Windows Explorer use Deflate64 compression for ZIP files larger than 2GB, but Python's standard zipfile module does not support this format. The package wraps the infback9 Deflate64 decompression library (from zlib) and monkey-patches Python's zipfile module to recognize and decompress Deflate64-compressed entries transparently.

When imported, the package modifies the standard zipfile module in-place, so any subsequent calls to zipfile.ZipFile() automatically gain Deflate64 support. It re-exports the entire zipfile API for convenience, allowing you to use it as a drop-in replacement. The package has no runtime dependencies and is distributed as precompiled wheels for common platforms and Python versions.

Use it for:

- Extract large ZIP files created by Windows Explorer's native compression feature without external tools.
- Process ZIP archives from Windows systems in a Python application that previously failed on Deflate64 entries.
- Automate handling of mixed-compression ZIP files where some entries use standard Deflate and others use Deflate64.
- Replace manual workarounds (e.g., calling 7-Zip or p7zip CLI tools) with a native Python solution.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

Enables extraction of Deflate64-compressed ZIP archives using Python's standard zipfile API, patching the module to support a compression format that standard zipfile cannot handle.

Yes, if you need to extract Deflate64 ZIP files in Python and have no other decompression tool available. The package is straightforward to use and has no runtime dependencies. However, note that it is dormant (last release January 2022) and may not receive updates for future Python versions; verify compatibility with your target Python version before relying on it in production.

## Install

pip install zipfile-deflate64
uv add zipfile-deflate64
poetry add zipfile-deflate64

## Installing zipfile-deflate64

Before you install: Medium install friction due to compiled wheels; the package is dormant (last release January 2022, no commits since December 2023) but has prebuilt wheels for Python 3.6–3.10 on macOS, Linux, and Windows, reducing runtime compilation risk.

License in practice: Apache 2.0 is permissive; you may use, modify, and distribute this package freely in commercial and private projects with minimal restrictions.

Quickstart:

pip install zipfile-deflate64

import zipfile_deflate64
# Now standard zipfile.ZipFile() can extract Deflate64 archives
import zipfile
with zipfile.ZipFile('archive.zip') as z:
    z.extractall()

Requires Python 3.6 or later; the package monkey-patches the standard zipfile module on import, so it must be imported before zipfile operations.

Verify before relying:

- Whether the package works correctly with Python versions beyond 3.10 (fact sheet lists support only through 3.10).
- Current maintenance status and likelihood of updates for newer Python releases or security issues.
- Performance characteristics when extracting very large Deflate64 archives.

## Package facts

- License: Apache 2.0 (permissive)
- Python support: supports_current
- Install friction: medium
- Maintenance: dormant
- Downloads: 1.1M/month (top 5,000 on PyPI)
- Known vulnerabilities: none known

## Tags

deflate64 zip extraction, windows zip deflate64 support, large zip file decompression, zipfile deflate64 python, extract deflate64 archives, zip compression format support, zip-compression, windows-compatibility

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